Oil-burning and control apparatus



A ril 22, 1952 w. H. PAYNE 2,594,206

OIL-BURNING AND CONTROL APPARATUS Filed March 26, 1947 H WM 'i speeds.

Patented Apr. 22, 1952 UNITED STATES PATENT OFFICE OIL-BURNING AND CONTROL APPARATUS William Harvey Payne, Hinsdale, 111. Application March 26, 1947, Serial No. 737,211

6 Claims. (01. 158-23 A either the on and off type, which provided full heat or no heat, or of the high and low type, which provided high or low heat. Thesehave generally been-regulated between high heat or low and off, by a temperature responsive means. positioned in the chamber which was alternately being heated, or sometimes in the path of the heating medium flowing to said chamber.

With only a small number of available rates for the supply of heat, there was necessarily considerable fluctuation over short periods of time of the temperature of the medium heated by the burner. These were sometimes very objectionable. According to the present invention, a practical means is provided for varying the supply of heat through infinitesimal increments so that it can exactly balance therequirements. In addition, the control is obtained through a temperature responsive device in the path of the heating me--- dium passing from the heated chamber to the burner so that the exact amount of heat is supplied which is required to raise the heating medium to the particular temperature desired.

. Efficient burning is maintained in spite of the infinitesimal variations by maintaining approximately a constant proportioning of air and oil,

both being delivered by displacement pumps which are driven at the same or proportional used, and for some aspects of the invention another fuel, such as gas, may be used.

In spite of the variations in rate of delivery of the oil, the discharge pressure is maintained approximately constant by a discharge valve which is biased toward the closed position during operation. In the preferred form of the invention, the biasing force is magnetic and is automatically discontinued when the burner'is shutofi' so that oil can drain from the burner so as not to be carbonized by remaining in the hot burner. A special storage chamber is provided for storing air pressure which is automatically released to blow the oil out of the burner as the burner is being shut down.

Additional objects and advantages of the invention will be apparent from the description and from the drawings in which:

Figure l is a largely diagrammatic view of the form of the apparatus chosen for illustration of the invention, a heating unit being shown in vertical cross-section; and

Fig. 2 is a perspective view showing a battery of three core ovens with the heating unit oi 1 on top thereof.

Other proportioning devices may be,

. 2 Fig. 3 is a diagrammatic tion. Although the law requires a full and exact deview 01' a modificascription of at least one form of the invention,

bers. L'Iheelir'hzited'by heater I I is circulated through the ovens by blower I3.. A con'duit H connects the heater with the blower, conduit 16 connects the blower with the ovens, and conduit [1, one of which is not shown, connects theovens with the intake chamber of the heater unit ll.

The heater unit As seen in Fig. 1, the heater unit H may inelude an intake chamber 2|, a combustion chamber 22, and a mixing and outlet chamber 23. Air and gases which have given off their heat in the ovens l2 enter the heater through-chamber 2|, which maybe considered part'ofthe return duct, are heated by the flame in combustion chamber 22, and pass through chamber 23. From the chamber 23, the heated gases flow through the blower l3 back to theovens.

Burner The burner comprises an outer air flow tube 26 and an inner oil flow tube 21. The tube 21 together with spreader or valve 28 forms a nozzle from which the oil is sprayed into the incoming air. Any suitable means may be combined for starting combustion but thereafter it continues as long as the oil and airare supplied.

Proportional feed Oil is supplied to the inner tube 21 by a pump 3| which is preferably a gear pump. or other type of displacement pump. Air is supplied to the outer tube 26 by a pump 32 which is also preferably a displacement pump, such as a Roots type blower. By a positive displacement pump is meant any pumpv in which the discharge per revolution is approximately constant, regardless of the pumps speed. Thus, the rate of discharge is independent of pressure and the rate of discharge per minute is proportional to the speed of the pump. The pumps 3| and 32 are driven at speeds which bear a fixed proportional relation to one another, preferably being driven at the samespeed. Thus, they will always feed oil and air at a givenvolume ratio. In theillustrated form, they are both driven by a motor 33 which isa variahleispeed, direct .current motor of the shunt type.

Control system.

According to one feature of the present invention, the proper quantities of'fuel- -and' air are at all times supplied to bring the temperature of the incominggases up to a, predetermined value? The amounti'o'f. fuel and air required is, 'lIl*fiQl3,- d-- te'rminedby thermocouple 35 located intheair to be re heated- It will be understood that the volumefiof gases.tobeqheated is constant, blower .li3 being'fa conventionaltype'without' speed yariationcontrol, diagrammatically illustrated-"in IE'i'g,.;.1,fjthe thermocoupl'eiiii's connected-to anamplifier l3?! which. in turn. is..connected to a torque .motor. 133'. .Thejtorgue mot'or'38' drives a contact varmlall' of a rheostatto. vary theamount ofr'esistance 41 connected in the field circuit of the ..motor.. ."-Ihe"field coil has been illustrated as aihuritifild with theiresult that its excitation determines. thespee'd atl'which' the; motor '3 3' operates and',.hence,j thespee'd at'which 'pumps' 3| "an 32 operate. 1 V

.If the. temperature of the incominggases' in chamber 2 l drops, thermocouple '36 calls for more .heat and .causes...rheostat arm 13 92130 moveto the po'sitionwhichwill; drive. motor 33tandgpumps 3 I ,iexoessive. makes theJnotor atzrunat.mini- Jmum.-':speed; If desired, the .relay 48. could" be ;connected' to shuntout onlya. small and perhaps -=adjustable part of resistancemdli so thatv it. would merely slightly decreasethe speedofmotor 33;

The relay 48 maybe designed or adjusted to act either with slow" reaction as a limit switch to gpreventwyery serious overheating, .or with quick .reaction tomodulate the average speed offithe' motoriwhena temperature only slightly abovethe desired temperaturev is reached. "In .tlie'l'atter case, itwill function more frequently, atfl'east if the regulation ofpump. motor 3.3..is designed to provide a slight excessmof' .the...desiredfheat so as never to fall materially below the required level. Alternatively, the heat. ;responsive element 46 -couldbe. connectedto. cause the supply of a slight additional increment. of j'heat whenever its" tem perature :fallsbelowa predeterminecl'value. Its

.usev as allimit' switch with regulation of the motor 33i.by..rheostat arm 3.9. :as accurately asimay ,be

desiredlis.preferredifinasmuchias this w'illi'givethe mostuniform'heat;

i-Theentire control and drive apparatusmay'be poweredby any suitablesourceof direct'current. The direct current may be obtained from alternating current supply wires 5| connected to a rectifier diagrammatically indicated at 52.

Oil drainage from hunter 7 In order that the oil be sprayed at substantial pressure in a thin sheet when the volume is low 7 as well as when the volume is high, the spreader or spray plate 23 is preferably mounted and is urged toward the closed position. The biasing means preferably acts with approximately constant force during operation so :asto maintain .a. uniform oil pressure. A varying biasing force could be provided if preferred. Itis desirable that ftheibiasingzforce be-discontinued when the burner ceases to operate, so that oil whichfmight other" wisebetrappedin the burner can escape. This .iprevents,carbonization of the oilunder the influenced. theheat of the furnace. One method 'o'f' biasing the spray plate 28 during operation and leaving it unbiased at other times is by a "solenoid St-which: maybe connected to the main :pcrwerwires ifil'asshown Theconnection may :be ianywherejin which itis subject to' de-energization iwhenevercontrolswitch 58 is operated to shutfoff :the::mot0r-33.. .In place of the simple-solenoid 53'v illustrated, :a-motor-could bee-used (Fig. 3-) with the-rotor 58' connected to: the stem'5'1 of :spray :plate 28"soas to rotate this spray plateto cut'up slugs ofheav y oil or .evenroll any harder particles :so" -that .they I can pass through the "burner; In this event, .therrotor 58 would be axially displaced from: then-magnetic center ofstator-SG so that imagne'tismrof the: motor would bias the stem :51 and spray .zplate za-m .the: closing direction.

:tspring; biasing; ;means zc-ould alternatively be used-with: a limit device to :prevent the-spray plate: it-from quite-closing .ongthe burner; nozzle.

.Discharge ofzthez-oikmay becensured-hyiproviduirrg:meansi-for blowing. itcut. of the burner.- atter shutdownof; thezapparatus. .Ijo :this end; an air rstoragei-tankzor chamberzfiil may beprovidedwith check yalvesGZz-and 63 arranged as. diagrammatically illustrated; During; :operation of the blower132; airiunderrpressure; is blown intostor- =age:chamber:6l .:Inasmuch'; as the oil "will be'un- .derr'a:still:liig'herrpressura;this air cannot escape through-.check:valvei63'. Thercheck valve itself prevents :entr-ance 70f oil in: theichamber 6 i. As therapparatusisrishut down, the-air. pressurerfrom blower; 32svrill';decrease. vbutxoheck'valve =52 will .preyentrescapeof air'through. it from. thechamber 6|. As the oilpressurexdrops due tostoppingiof the-pump '31 the :ciompressed air-in chamber 6 I will open .:'check. valve 63 and'e'scape through the oil burnerrconduit I 21 blowing'from the I oil .burner *conduit 21. the oil which might otherwise car- .iboniza.

Totprevent seepagepf oil whenpump 31 is'n'ot operating-15a valve 64 is provided. If the oil level is always below the burner; thismaybe a simple check. valve. Iffthe oil level-is as high-as "the burner; :the valve: 6 4 is. loaded" with sufficient bias ingtforcettosclose inspite of theihydrostaticjpres- :sureiof the oil, although-of course; opening under the greater pressure resulting fromqactuationof -.pump 3l :It will be understood that'many variationstmay be made from theiillustrated :embodiment :now

preferred. Although displacement pumps will giveflther; most ipositiveiproportioning-g other .lclnds aof pumpsm'ould' housed, at least if th'etwo pumps are of similar type and balanced 'so that the proportions of -air and oil remain constant at different speeds. 1

Although a variable speed motor'has-been illus tion of the regulating device does not vary as a result of variations in the torque value moving it. In that event, the follow-up system may be made responsive to the position or the torque motor 38 or it may be made more directly responsive to the heat responsive element 38.

Although the invention has been disclosed in connection with oil, it is apparent that gas or other fuel could be burned with suitable changes in the mechanism, the control remaining virtually the same. In the case of gas, gas at constant pressure could be pumped by a gas pump or blower in the position or pump 3|. Alternatively, a valve could be opened varying amounts correlated with the varying speeds of the air blower 32. With a stoker, the blower and stoker feed could be jointly driven. The stoker feeds are conventionally of a displacement type such chamber to the oil conduit to blow oil from the nozzle as the pressures reduce in shutting off the apparatus.

2. Oil burning apparatus including a burner having an oil conduit and an air conduit. each terminating at a nozzle, a spray plate adjacent the oil nozzle opening, and biasing means for urging said nozzle spray plate toward said opening including an electromagnetic unit energized when said oil burning apparatus is operating, and at other times being de-energized and releasing said spray plate.

3. Oil burning apparatus including a burner having an oil conduit and an air conduit, each terminating at a nozzle, means for constricting the discharge of oil to maintain a pressure for throwing a stream, and blow-out means including a storage chamber, a check-valve connection as a screw conveyor. By using a blower oi the displacement type as previously indicated, the proportions of fuel and air would be approximately constant at the varying speeds.

It will be recognized that instead of the direct it heating system illustrated, an indirect system may be used. In that, the burner and combustion chamber are separated from the circulating 1."

medium so that the latter is not mixed with the products of combustion.

From the foregoing it is seen that a heating and fuel burning apparatus has been developed in which the amount 01' heat supplied is exactly the amount required to bring the temperature; oi the heating medium to a desired value. This has a wide range 01 possible usefulness, even being adaptable to house heating. It is most advantageous in combination with a modulating type of burner or heat generator. It is also seen that a modulating oil burning apparatus is pro- 1 vided in which the proportions of fuel and air are constant in spite of a wide range of minute variations in their volumes. In the case oi. an oil burner, the oil is maintained under approximately constant pressure so as to be satisfactorily sprayed from the oil nozzle at diflerent speeds,

having an oil conduit and an air conduit, each terminating at a nozzle, a spray plate adjacent the oil nozzle opening, biasing means for urging said nozzle spray plate toward said opening, in-

cluding an electromagnetic unit energized whensaid oil burning apparatus is operating, and at other times being de-energized and releasing said spray plate, and blow-out means including a storage chamber, a check-valve connection from the air conduit to the storage chamber to fill the storage chamber with air under pressure,

and a check valve connection from the storage from the air conduit to the storage chamber to fill the storage chamber with air under pressure, and a check valve connection from the storage chamber to the oil conduit to blow oil from the nozzle as the pressures reduce in shutting off the apparatus.

4. Oil burning apparatus including a burner having an oil conduit and an air conduit, each terminating at a nozzle, a spray plate adjacent the oil nozzle opening, and biasing means for urging said nozzle spray plate toward said opening including an electromagnetic unit energized when said oil burning apparatus is operating, and at other times being de-energized and releasing said spray plate, means for supplying oil and air to said burner including a displacement type oil pump, a displacement type air pump, and means for driving said pumps with their speed relationship fixed proportionally,-but with their speed jointly varied.

5. Oil burning apparatus including a burner 2 having an oil conduit and an air conduit, each terminating at a nozzle, a spray plate adjacent the oil nozzle opening, and biasing means for urging said nozzle spray plate toward said opening including an electromagnetic unit energized when said oil burning apparatus is operating, and at other times being de-energized and releasing said spray plate, means for supplying oil and air to said burner including a displacement type oil pump, a displacement type air pump, and means for driving said pumps with their speed relationship fixed proportionally, but with their speed jointly varied, and blow-out means including a storage chamber, a check-valve connection from the air conduit to the storage chamber to fill the storage chamber with air under pressure, and a check-valve connection from the storage chamber to the oil conduit to blow oil from the nozzle as the pressures reduce in shutting off the apparatus.

6. Oil burning apparatus including a burner having an oil conduit and an air conduit, each terminating at a nozzle, means for spraying oil and air respectively to said conduits in fixed proportions but at varying rates to modulate the burner, a spray plate adjacent the oil nozzle opening, biasing means for urging said nozzle spray plate toward said opening, including an electromagnetic unit energized when said oil burning apparatus is operating, and at other times being de-energized and releasing said spray plate, and blow-out means including a storage chamber, a check-valve connection from the air conduit to the storage chamber to fill the storage chamber with air under pressure, and a check valve connection from the storage chamber to the 

